First, dramatic revelations from kelly preston, about the death of her 16-year-old son. For the first time, she was talking about the illness that jett travolta suffered. And why she thinks he passed away four years ago from a seizure. Bazi kanani is here with all of the details. Good morning, bazi. Reporter: Good morning, elizabeth. Kelly preston has done other interviews since her son passed away. But the death was not a topic she discussed. She is deciding to speak out it now, hoping it will be a warning to other families. Kelly preston and wife of john travolta, has lived most of her life in the spotlight. But there's one thing she kept quiet about for four years. Until now. He was autistic. And he had seizures. Reporter: For the first time, preston is publicly acknowledging her late son, jett, had autism. She is also talking about what she believes caused it. I strongly believe, as a mother, and as does my husband, that there are certain contributing factors that lead to autism. Reporter: Their 16-year-old son died nearly four years ago, after suffering a seizure, while the family was on vacation in the bahamas. He had come close to death one time before, as a toddler. Back in 2001, john travolta told abc news, jett was hospitalized for a rare autoimmune disease, called kawasaki syndrome. We thought we were going to lose him. Reporter: On wednesday's edition of the tv talk show, "the doctors," preston claims there were several factors contributing to jett's autism. Her young son had been exposed to carpet cleaning chemicals. But she believes his medical problems could have started everyone earlier, in the womb. I had food poisoning when i was five months egnant. That can change a lot of things in your body. That's very much a toxin in your body. Reporter: Preston said she took medicines during labor. And more while breast-feeding. There were contributing factors, plus the kawasakis, that I believe absolutely why he had autism. And why he had seizures. Reporter: The 50-year-old mother of two other children, is now an advocate for an organic, chemical-free lifestyle, believing her heartbreak could have been avoided. Preston said her family had started to make a change to an all-organic, chemical-free lifestyle before her son died. She said it was helping him, quote, that he was coming out of autism. Although, many in the medical community do not believe there are known cures to the disease.

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